1. Field of the Invention
The present invention relates to structural laminated wood and construction members for framework structures of buildings utilizing the structural laminated wood.
2. Description of the Related Art
From the results of dedicated research carried out over many years, the present inventor has developed a joint apparatus for construction members which is simpler than the simplest conventional coupling methods, for example methods involving various combinations of iron plates and bolts and nuts, and strengthwise is superior to the time honoured wooden cut out method.
This will be apparent from the disclosure of Japanese Examined Patent Publication No. 6-57977.
With this joint apparatus, standardised pre-cut members can be used for the construction members. This joint apparatus is the one for construction members comprising suitable standardized joint members which makes it possible to couple the standardized pre-cut members to form the framework of a building. This apparatus can thus construct frameworks applicable to buildings and the like, which combine both the features of the customary framing method and built-up wall method.
In constructing such a building, structural laminated wood L.V.L (laminated veneer lumber) is used for the construction members making up the framework structure.
Structural laminated wood is formed for example by thinly slicing a log by a rotary lathe, after which thin sheets (wood laminas) formed by cutting are dried, and a plurality of the thin sheets then bonded together using adhesive. Compared to normal laminated wood, this has a high allowable strength and waterproof.
This type of structural laminated wood is used as vertical construction members for example columns, and as transverse construction members for example beams.
However, since conventional structural laminated wood for columns (referred to hereunder as laminated columns) and structural laminated wood for beams (referred to hereunder as laminated beams) is formed in various simple rectangular shapes, there are the following problems.
That is to say, with the corner portions of a framework structure as shown in FIG. 7, a laminated column 1 and a laminated beam 2 are joined by jointing devices 3 (bolts and nuts; drift pins).
In this case, since the joint portion between the laminated column 1 and the laminated beam 2 is subjected to a moment due to transverse forces, it is necessary to have a rigid joint portion construction resisting the moment. For example as shown in FIG. 7, the location of the jointing devices 3 must be positioned on a circle or the like. Hence the jointing operation takes time.
In general with buildings, the construction is such that the transverse forces applied to the building due for example to earthquakes or strong winds is resisted by the wall structure and bracing.
For example as shown in FIG. 8 and FIG. 9, it is possible to make up a bearing structure such as a wall structure and bracing for the open portion of a room.
However, when making for example a parking area on the first floor area of a building, if the transverse width of the building is narrow, it is all to maintain the width of the entrance to the parking area. Hence it is not possible to have a bearing structure formed by a wall structure and bracing, on the opposite sides of the entrance.
Therefore, the first floor area of the building will not be resistant to transverse forces applied to the building due to earthquakes, strong winds or the like, resulting in a framework structure of poor strength.